Manufacture of forging blanks



June 10, 1941. N

MAN ET'AL 2,244,852

June 10, 1941- N. c. RENDLEMAN ETAL HANUFACTURE OF FORGING BLANKS Filed July 9, 1938 4 Sheets-Sheet 2 INVENTQRS Norma/1C. Rend/eman Burges A. L emonfe June N. c. RENDLEMANY ETAL ,85

MANUFACTURE OF FORGING BLANKS Filed July 9, 1838- 4 Sheets-Sheet 3 \zes m:

June 10, 1941. N. c. RENDLEMAN ETAL 2,244,352

IANUFACTURE OF FORGING BLANKS Filed July 9, 1938 4 Sheets-Sheet 4 INVENTORS g/orman fifndleman ur es emonfc 7 m @2275 Patented June 10, 1941 MANUFACTURE OF FORGING BLANKS Norman C. Rendleman and Borges A. Le Monte,

assignors Pittsburgh, Pa,

to Jones and Laulhlin Steel Corporation, Pittsburgh, Ya, a corporation of Pennsylvania Application July 9, 1m, Serial No. 21am 6 Claims. (01.80-27) This invention relates to the manufacture of forging blanks such as are widely employed in the shaping of various articles of commerce which require to be forged. I

Forging blanks are employed to facilitate and expedite the forging operation, but the blanks which have been employed heretofore for the manufacture of certain articles of more or less complex finished shape have accomplished this object only imperfectly. Blanks as manufactured heretofore have proved satisfactory for certain articles. The forgingof other types of articles from such blanks, however, has involved material while positioned in each set of dies,-

whereby a corresponding increase in die life is obtained.

In accordance with our invention, we flatten V and spread, preferably by die rolling, longitudinally spaced portions of a leader which may initially be substantially circular, or of other shape, in cross section. Thereafter, we true the edges of the flattened and spread portions to conform substantially with the initial dimension of the leader. This provides a string of blanks, each including spaced masses of metal having substantially the section of the original leader, connected by portions having one cross sectional dimension which is substantially that of the original leader, the other dimension thereof being considerably less than the corresponding dimension of the leader. By the aid of our invention, an improved type of forging blank may be produced at relatively low cost. What is more important, the invention provides forging blanks from which relatively complex shapes can be forged expeditiously and economically. The invention not only simplifies the forging practice, but involves only relatively simple rolling operations.

A complete understanding of the invention will be obtained from a study of the following detailed description thereof, with reference to the accompanying drawings illustrating a present preferred practice for the manufacture of two types of forged articles. In the drawings:

Figure 1 is a partial side elevation of a roll pass which we prefer to employ for forming flattened portions spaced longitudinally of a leader;

Figure 2 is a partial sectional view on the line II-II of Figure 1;

Figure 3 is a section of a roll pass which we prefer to employ for truing the edges'of the flat-- tened portions of the leader, the section being taken on a plane containing the axes of the two rolls defining the pass;

Figure 3-A is a diagrammatic showing in side elevation, of a mill adapted to carry out the method of our invention;

Figure 4 is a plan view of a leader including longitudinally spaced portions which have been flattened and spread inthe first step of the manufacture of a fo ging blank for connecting rods in accordance with the invention;

Figure 5 is a side elevation thereof;

Figure 6 is a sectional view taken along the line VI--VI of Figure 5;

Figure 7 is a plan view of a finished forging blank made in accordance with the invention;

Figure 8 is a side elevation thereof;

Figure 9 is a sectional view taken along the line LIX-IX of Figure 8;

Figure 10 is a. plan view of the forging produced from the blank shown in Figures 7 through- 9 with the forging flash thereon;

Figure 11 is a view similar to Figure 2 showing die rolls for manufacturing blanks for a different type of article such as a cam shaft;

Figures 12 through 14 are sectional views taken along the correspondingly numbered lines of Figure 11, showing the shape of the pass provided by the rolls of Figure 11 at different stages in their rotation;

Figure 15 is a plan view of a leader for the manufacture of forging blanks for a different article after the first operation according to our invention;

Figure 16 is a side elevation thereof;

Figures 1'7 and 18 are sectional views taken along the correspondingly numbered lines of Figure 16;

Figure 19 is a plan view of a leader which has been formed into a string of forging blanks by the final operation in accordance with our invention; I

Figure 20 1s a side elevation thereof Figures 21 and 22 are sectional views taken along correspondingly numbered lines of Figure 20; and

. of may be effected. 'Iheport-i'oii betwee "with their axes substantially horizontal.

leader is indicated at 25, the partly formed string of'blanks at 2B, and the finally formed string at 21. Since the grooves IS in the rolls 20 and 2! are of uniform depth around the periphery of the rolls, it is unnecessary to cause the partly reduced leader to enter the final pass at any particular point in the rotation of the rolls 20 and Since the pass between these rolls is substantially circular, furthermore, it is immaterial The portion l3 of the leadenbetween the-fiattened portions l and il remains substantially undeformed, although a slight reilu'ction' t "ere flattened portions H and i2 antibeyond tlie flattened portion Iii are subjected to a slight r duction in diameter.

The flattening and spreading operation may carried out by passing the leader between die rolls such as those shown at M and IS in Figures 1 and 2. As there indicated, the rolls i4 and; i have matching matrix grooves i6 therein includ ing depressions H and high spots i8. It will be understood that a string of partly formed blanks, such aslndicated-in Figurese and 5 will'resuit from the passage of 'a leader h'eated. to proper rolling temperature,. through one of the passes defined bycooperating grooves "lfi in the rolls i4 and i5. As indicated indotted line's'jin,

Figures 4 and 5, the-similarly shaped ends' o'f successive blanks in the string lie' adjacent ,each other.

As shown in Figures 4 and 6, the portions i0, Ii, and I2, which are flattened in the die rolling, exhibit substantial spreadingor widening beyond the diameter of theportion 13, which isreduced only slightly from .theoriginal diameter of the leader. We finish thestring of partly formed forging blanks resulting from ;;'aa ssi ngv the lead er through one of the passesv between the rolls i4 and I5, by truing'the edges of the flattened portions l0, Ii, and I2 to 'fconforinsubstantially to the diameter of the "portion 13, Weprefer to do. this by passing the "stringof partlylforrned blanks through a substantially circular roll pass,

such as that defined by cooperating grooves i9, formed in rolls 20 and 2 i The flattened portions I0, I i, and [2 only of the string of partly formed blanks are reduced by the rolls 20' and 2!, the

portions i3 retaining substantially thefull diam eter they have after passing between'rolls i4 and IS. The truing ,offthe edgesfof'the flattened portions of the blank's'fexerts a slight elongating effect on the latter, as will be apparent by a'coinparison of Figures 4 and 5 with Figures '7 and 8.

"Figure 9 illustrates that the-edges of theflatten'e'd portions l0 and II 'are'trued'by passing between the rolls 20 and 2| to conform to the diameter of the portions i3, an'd that all pore tionsof the blanks lie within a cylinder having a diameter not materially less than that of the original leader.

Blanks may be conveniently made according to our invention by apparatus illustrated diagrammatically in Figure 3-A. As there shown,

" -with ith major axis precisely horizontal or not.

whether the partly finished string enters the pass Asaillustratedin Figures '7 and 8, a finished blank comprises spaced masses of metal 28, 29

' and '30, connected-by intermediate portions 3i,

havingv aidimension in one direction substantially the's'a'meas' that of the portions 29 and a di- F 'mensioh' considerably less in the other direction. The finished blank is also provided with a tong hold 32.

- A -blank such as shown in Figures 7 and 8 is intended for the forging .of connecting rods such I as thosflsho'wn' at 33 and 34 in Figure 10, each blankcontaining metal masses properly spaced and of'sufiicient size to form a pair of connect- ..ing rodsdisposed ln opposition. The conversion ofabl'a nk suchas that shown in Figures 7 and B'to'a' finished forging such as that shown in Figure' 10 requires several forging operations which are knownand" hence require no description. It is sufficient to state that the masses and 3B of a blank furnishthe metal necessary to form the wrist'pinends'of the connecting rods, while the mass 29 furnishes the metal necessary to form the'crank shaft ends. The metal forming the intermediate portions of the connecting rods is provided by the intermediate portions 3| of j the blanki' The excess metal is disposed of by 1 the'formation of forging flash 35 which is subsequently sheared off with the tong hold 32 preparatqry to machining operations on the forged c'onnec'tingrods. This constitutes scrap and it is 'a further object er our invention to reduce the amount"ofthis'scra'p to a minimum.

I 'Oiir" invention is applicable also to the manufactu're of blanks from which other articles, such as" the cam shaft shown in Figure 23 may be con- -"-yeniently forged. About the only difference ber in the die rolls.

tween the manufacture of blanks for a cam shaft and that for the manufacture of connecting rods is in the disposition of the metal masses in the blank,-and therefore, the contour of the grooves The latter, as shown at 35 and "31 in Figure 11, have their depressions 38 and 39 I and high spots 40 so located as to distribute the metal properly in the finished blank.

A'partially formed blank for the manufacture of acam shaft is shown in Figures 15 through 18 and comprises a leader initially circular in section having longitudinally spaced flattened and spread portions 40 and 4 i Intermediate portions 40 and H are metal masses 42 which, with respect --to the initial size and shape of the leader, are

the rolls i4 and I5 are those ofa die rolling mill indicated generally at 23 and are 'disposed crating with the mill 23 is a mill stand 2d having vertical rolls 20 and 2| journaled therein"*-= As shown in Figure 3A, the stands 23 a'li'clfl' engage a leader simultaneously andbpratejthereon in the manner of the stands of continuous mill. In Figure 3-A the origin'alfunreduced,

Cooponly slightly reduced.

The step of converting a string of partly formed blanks, such as shown in Figures 15 through 18,

into a string'of finished blanks, such as shown in Figures19' through 22, is identical with that described in connection with the manufacture of forging'blanks for connecting rods. The string of partly-formed blanks issent through a pass, "such as that of Figure 3, which converts it into a P string of finished blanks, as shown in Figures 19 through 2 2. 'The blank of Figure 19 differs from '--the 'ur'ifiz'iished blankof Figure 18 in the same annerfastheblank of Figure 7 differs from the partiy formed blank of Figure 4. The edges of the flattened portions are trued to conform to the diameter of the slightly reduced portions 42 and are elongated as a result. This elongation is slightly more pronounced in the case of a blank such as that of Figure 19 because of the greater length of the reduced portions lll thereof as compared to those of the blank shown in Figure 4.

A forged cam shaft, as shown at 43 in Figure 23, may be formed by subjecting a blank such as that of Figure 19 to successive forging operations in the known manner. As in the case of the connecting rod forging, the masses 12 of the finished blank furnish the metal for the larger portions of the cam shaft such as the journals M. The metal for the smaller portions, including the body of the shaft 45 and the earns 46, is provided by the reduced portions 0 and 4i, the excess metal being converted into flash ll during the forging process. A tong hold for the cam shaft is provided at ll.

It will be apparent from the foregoing description that the invention provides forging blanks and a method for the manufacture thereof which are characterized by numerous advantages over such blanks and methods as heretofore employed. In the first place, forging blanks according to my invention weigh less than the blanks heretofore used for similar articles. This means that a greater number of. articles can be obtained from a ton of material and since semi-finished steel is furnished on a tonnage basis, the resulting reduction in the cost of the finished article is evident. In the second place, the number of different sets of dies necessary to convert the blanks to the finished articles is reduced. This represents a material saving since forging dies are quite expensive. A further saving results from the fact that fewer hammer blows are necessary for. each forging operation, that is, each set of dies. This not only reduces the wear on the dies, but increases the output per operator. The increased die life resulting from a reduction in the number of hammer blows on each set of dies for each article forged causes a still further reduction in the over-all cost of the finished article. The reduction in the number of forging operations also increases the output per man hour.

Further advantages have already been referred to, such as the use of a simple form of leader, 1. e., round bar stock, and the absence of difficult rolling operations. The equipment for manuiacturing the blanks, furthermore, is relatively simple and inexpensive to construct and maintain.

A further advantage of the invention is that it is not characterized by certain objectionable results inevitably encountered in die rolling as previously practiced, viz., the increase in the weight and the decrease in the length of the blank as the roll impressions wear. We are able to compensate for such wear by bringing the rolls closer together as wear occurs, thus maintaining constant the weight of a unit length of the blank string or the weight per blank, and also the length of the latter. By thus manipulating the rolls, we are able accurately to control the dimensions of each cross section, and to avoid the waste entailed by exceeding the minimum required weight per blank.

We have referred chiefly herein to the use of a leader circular in cross section but the invention is also applicable to leaders of other shapes such as oval, elliptical, diamond, and the like with equal facility and advantage.

Although we have illustrated and described herein but one preferred practice of the method and two forms of blanks which the method is capable of producing, it will be understood that changes in the process or shape of the blank may be made to accommodate a variety of articles now manufactured by forging, without departing from the spirit of our invention or the scope of the appended claims.

We claim 1. In the method of hot rolling forging blanks, the steps consisting in passing a heated leader bar between die rolls having spaced matrix portions of lesser height and greater width than the leader bar and adapted to flatten and widen longitudinally spaced portions of the leader bar, maintaining the intermediate portions of the leader bar at approximately their original cross section, passing the deformed leader bar between plain grooved rolls providing a round pass, and thereby exerting pressure on the bar in a direction generally at right angles to that exerted by the die rolls, so adjusting the plain rolls that they engage the widened portions of the deformed bar and so reduce their width that they are at no point wider than the intermediate portion, and maintaining the intermediate portions at approximately their original cross section.

2. In the method of hot rolling forging blanks, the steps consisting in passing a heated leader bar of substantially circular section between die rolls having spaced matrix portions of lesser height and greater width than the diameter of the bar andadapted to flatten and widen longitudinally spaced portions of the bar, maintaining the intermediate portions of the leader bar at approximately their original, substantially circular cross section, advancing the deformed leader bar, toward a substantially round pass between grooved, plain rolls, said plain rolls also being at right angles to the die rolls, said round pass being only slightly smaller than the section of the original leader bar, entering the leader bar into said round pass before the bar leaves the die rolls, without regard to the angular position of the major axis of the section of said portions relative to the axes of the plain rolls, and thereby exerting pressure on the bar in a direction generally at right angles to that exerted by the die rolls, so adjusting the plain rolls that they engage the widened portions of the deformed bar and so reduce their width that they are at no point wider than the intermediate portions, and maintaining the intermediate portions at approximately their original cross section.

3. In the method of hot rolling forging blanks, the steps consisting in passing a heated leader bar between die rolls having spaced matrix portions of lesser height and greater width than the leader bar and adapted to flatten and widen longitudinally spaced portions of the leader bar,

maintaining the intermediate portions of the leader bar at approximately their original crosssection, passing the deformed leader bar between plain rolls, and thereby exerting pressure on the bar in a direction generally at right angles to that exerted by the die rolls, so adjusting the plain rolls that they engage the widened portions of the deformed bar and reduce the width of said portions to the diameter of the unflattened portions of the bar, thereby producing a string of connected blanks all parts of which lie within a cylinder having a diameter not substantially less than that of the original leader bar.

4. In the method of hot rolling forging blanks, the steps consisting in passing a heated leader bar between die rolls having spaced matrix portions of lesser height and greater width than the leader bar and adapted to flatten and widen longitudinally spaced portions of the leader bar, maintaining the intermediate portions of the leader bar at approximately their original crosssection, passing the deformed leader bar through a substantially circular pass between plain grooved rolls, and thereby exerting pressure on the bar in a direction generally at right angles to that exerted by the die rolls, so adjusting the plain rolls that they engage the widened portions of the deformed bar and so reduce their width that they are at no point wider than the intermediate portions, and maintaining the intermediate portions at approximately their original cross section.

5. A continuous mill for manufacturing forging blanks comprising a stand of die rolls effective to flatten and spread longitudinally spaced portions of a leader passing therethrough and a succeeding stand of rolls at a substantial angle to the die rolls and providing a substantially round pass of constant size effective to true said portions to conform in width to the corresponding dimension of the unflattened portions of the leader, said stands being spaced apart by a distance less than the length of the leader whereby the leader is engaged by both stands during a portion of its rolling.

6. A continuous mill for manufacturing forging blanks comprising a stand of die rolls effective to flatten and spread longitudinally spaced portions of a leader passing therethrough and a succeeding stand of rolls at right angles to the die rolls and providing a substantially round pass of constant size effective to true said portions to conform in width to the corresponding dimension of the unfiattened portions of the leader.

NORMAN C. RENDLEMAN. BURGES A. LE MONTE. 

